The Core Unit will serve all of the projects on a highly interactive and collaborative basis. Four types of activities will be performed: 1. Animal Resource Management--The Core Unit will be responsible for all aspects of animal maintenance and health care, for carrying out animal pairing schedules, and for management of the animal records system. 2. Data Management and Analysis--The Core Unit will be responsible for management of detailed computerized life-history records on each animal, for management of experimental data associated with each animal (i.e., genotypic data, as well as phenotypic data related to cancer and lipoprotein endpoints), and for statistical analyses. Genetic analysis of data will also be carried out by the Core to test hypotheses regarding the role of genetic factors in UVR-induced lesion susceptibility. Research Support-The Core Unit will provide a variety of research services such as preparing special diets for research on lipoproteins, collecting and sorting blood and tissue samples from animals assigned to the various projects, conducting necropsies, and cooperating with the Department of Laboratory Animal Medicine (DLAM) in the provision of material for pathology services.